Garmin G3X Installation Manual page 197

A.3.6.2 Discrete Outputs
The GSU 73 has 2 annunciator outputs, these outputs do not require any configuration and can be
optionally wired to an external annunciator. Discrete Out 1 acts as a master warning annunciator and is
active any time a warning CAS message (Red Alert) is displayed on the PFD. Discrete Out 2 acts as a
master caution annunciator and is active any time a caution CAS message (Yellow Alert) is displayed on
the PFD. Reference Appendix G for wiring guidance.
DISCRETE OUT 1 is "master warning" - goes low when a red (warning) CAS alert is active.
DISCRETE OUT 2 is "master caution" - goes low when a yellow (caution) CAS alert is active.
The two states of these outputs are as follows:
INACTIVE: Floating (can be pulled up to externally sourced Vout in the range 0 ≤  V out ≤  3 3VDC)
Leakage current in the INACTIVE state is typically ≤ 10 uA to ground
ACTIVE: Vout ≤ 0.5VDC with ≤  2 0 mA sink current
Sink current must be externally limited to 20 mA max
Pin Connector
13 P731
14 P731
*Indicates Active Low
A.3.7 Analog Input Configuration
Some analog inputs are multi-purpose capable and have several configuration options. These inputs are
configured by the GDU (refer to Section 8).
If installing an ungrounded thermocouple to an Analog In input, a DC reference must be added to the LO
input. This can be accomplished by adding a resistance of 1 MΩ or less between ground and the Analog
In LO input that the ungrounded thermocouple is installed on.
Pin Connector
61 P732
41 P732
21 P732
1 P732
2 P732
22 P732
60 P732
40 P732
73 P732
53 P732
33 P732
13 P732
63 P732
43 P732
23 P732
3 P732
24 P732
G3X Installation Manual – Pinouts
190-01115-01
Pin Name
DISCRETE OUT* 1
DISCRETE OUT* 2
NOTE
Pin Name
CHT 1 HI
CHT 1 LO
CHT 2 HI
CHT 2 LO
CHT 3 HI
CHT 3 LO
CHT 4 HI
CHT 4 LO
CHT 5 HI
CHT 5 LO
CHT 6 HI
CHT 6 LO
EGT 1 HI
EGT 1 LO
EGT 2 HI
EGT 2 LO
EGT 3 HI
I/O
OUT
OUT
I/O
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
Page A-13
Revision E